Heated ballon medical apparatus with fluid agitating means

ABSTRACT

A method and apparatus for effecting necrosis of a tissue lining of a mammalian body cavity, particularly a uterine endometrium, by introducing an applicator comprising a distendable bladder connected to a catheter into the uterus, distending the bladder by introducing a non-toxic fluid under pressure, heating the fluid by means located internal to the bladder to a temperature of 190° to 215° F. and preferably 210° F. for a period of 4 to 12 minutes and preferably 6 minutes and regulating said apparatus by means located external to the uterus, thereby cauterizing substantially the entirety of the tissue lining, particularly the endometrium. An agitator circulates the fluid within the distendable bladder to help keep the fluid at a uniform temperature.

This application is a continuation of application Ser. No. 07/954,226,filed on Sep. 30, 1992 now U.S. Pat. No. 5,460,628.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to an apparatus and a method for treating thetissue lining of a human body cavity, particularly the endometrium ofthe uterus. More specifically, the apparatus and method of the presentinvention provides improved treatment, e.g., cauterization of theendometrium of a mammalian uterus, without many of the disadvantages anddangerous features of known techniques.

2. The Prior Art

The following terms as used herein have the meaning given below:

"Cauterization" means the application of heat to tissue in an amountsufficient to destroy the tissue.

"Necrosis" means the death of cells in tissue.

"Endometrium" is that portion of the inner lining of the uterus to whichan embryo normally attaches and excludes the portions of the uterineinner lining forming the cervix, to which the embryo usually does notattach.

Apparatus and methods for cauterization of the endometrium of amammalian uterus, useful in sterilization procedures and cancertreatments, are well known. Thermal and cryogenic treatments have beenutilized in such cauterization techniques and typically involve eitherthe direct or indirect application of heat or cold to the tissue to betreated.

For example, a laser hysteroscope has been used to cauterize theendometrial layer of the uterus. This laser treatment suffers fromseveral disadvantages. It requires the application of an intense amountof thermal energy to a relatively small area of tissue even though sucha large amount of heat may not be necessary to effectively cauterize thetissue. Further, this laser treatment requires the physician tocontinually reposition the laser used in the treatment within the uterusin order to treat the entire endometrium. Such internal manipulation ofa laser hysteroscope within the uterus of a patient is both difficult,requiring a significant level of skill to perform, and potentiallydangerous. Accidental puncture of the uterine or tissue wall may resultfrom manipulation of the laser scope within the uterus or body cavity,and tissue layers beneath the endometrium may be burned if a laser'sbeam is left focused on one area of tissue for too long a period oftime.

A variety of alternatives to laser treatment in cauterizing the uterineendometrium are known. In U.S. Pat. No. 3,924,628, Droegemueller et al.disclose a method and apparatus for necrosing tissue cells that utilizesan extendable bladder which is inserted in the uterus and filled with acirculating fluid or gas at cryogenic temperatures (referring totemperatures sufficiently low to cause cell necrosis). The bladderdisclosed by Droegemueller et al. is maintained in substantiallycontinuous contact with the inner surface of the uterine lining and issaid to achieve necrosis of substantially all of the uterine endometriumin a single treatment. Droegemueller et al. disclose the use of liquidnitrogen that vaporizes prior to introduction into the bladder, therebypressurizing the bladder to a level which ensures adequate contact withthe uterus. Other fluids disclosed by Droegemueller et al. as useful intheir method include refrigerants such as freon. Droegemueller et al.'smethod and apparatus suffers from the disadvantage of employingcryogenic fluids which could prove toxic to a patient in the event ofbladder rupture. Moreover, Droegemueller et al.'s apparatus does notallow precise regulation of the pressure used to inflate the bladder.Another disadvantage of Droegemueller et al.'s technique is thatcryogenic necrosis of the endometrium occurs at extremely lowtemperatures that pose a threat to tissue layers adjacent to the uterineendometrium. Droegemueller et al. and similar cryogenic techniques alsorequire the use of expensive equipment such as compressors and insulatedvessels associated with the storage and transmission of refrigerants.Moreover, Droegemueller et al.'s technique may require warming of thebladder in order to remove it from the body and minimize tearing of thesurrounding tissue which has adhered to the bladder during the freezingprocess.

In U.S. Pat. No. 2,734,508, Kozinski discloses a therapeutic apparatusfor applying dry heat to body cavities comprising an applicator that isintroduced in the body cavity while deflated and which is subsequentlyinflated and heated by means of circulating hot air. Kozinski does notdisclose an applicator which conforms to the shape of a body cavity.Further, given the lower heat transfer coefficients of gases as comparedwith liquid, treatment with Kozinski's apparatus should involve a longperiod of time in order to achieve necrosis, thereby exposing thepatient to additional discomfort and risk. Moreover, Kozinski'sapparatus does not provide for measurement and regulation of internalpressures and temperatures of the applicator introduced.

U.S. Pat. No. 2,077,453, issued to Albright, discloses a therapeuticappliance comprising a relatively long tubular applicator which isshaped and formed generally to the passage into which it is to beinserted and which has relatively thin elastic rubber walls thattransfer heat and which distend to fit irregularities of the treatedareas upon application of internal pressure. Albright also disclosesthat fluids such as heated water could be utilized as a heating means inhis applicator. The applicator of Albright, like that of Kozinski,however, suffers from the disadvantage that the distension of its wallsto conform to the irregularities of the endometrium is limited asAlbright provides an integral rubber web which serves to prevent unduedistension of the applicator. Moreover, Albright requires that the fluidbe circulated throughout the apparatus. Albright also does not providean apparatus that allows regulation of temperature and pressure of thefluid or other bladder inflation means.

U.S. Pat. No. 3,369,549, issued to Armao, discloses a therapeutic devicefor applying heat or cold to body cavities comprising a capsule probecontaining a heat exchanger and a flexible bladder that can be inflatedto conform to a body cavity. Armao does not, however, disclose a controlmeans for regulating the temperature and pressure of the flexibleapplicator, nor does he disclose cauterizing tissue in the cavity beingtreated.

Other patents that disclose the use of thermal treatment of the interiorlining of a body cavity include U.S. Pat. Nos. 2,192,768; 2,466,042;2,777,445; 3,369,549, and 4,949,718.

SUMMARY AND OBJECTS OF THE INVENTION

It is an object of the present invention to provide a safe andefficacious method for cauterizing the tissue lining of a body cavity,particularly the endometrium of a uterus.

It is another object of the present invention to provide a relativelyinexpensive and easy to replace applicator heated by a nontoxic fluidthat can be used to effect cauterization of the uterine endometrium andwhich is controlled by means external to the applicator.

It is another object of the present invention to provide an apparatusfor heating a fluid while it is in a bladder within the uterus and forintroducing the fluid under pressure into the bladder so as to assuresubstantially uniform contact of the bladder with the endometrium.

It is still another object of the present invention to provide anapparatus for regulating the temperature and pressure of the fluid inthe bladder while the bladder is within the uterus.

It is still another object of the present invention to provide anapparatus for maintaining a substantially uniform temperature of thefluid in the bladder while the bladder is within the uterus.

The present invention provides a method for effecting cauterizationnecrosis of the tissue lining of a mammalian body cavity comprising thesteps of inserting a distendable bladder into the body cavity; inflatingsaid distendable bladder to a predetermined pressure with a fluid sothat said distendable bladder is in contact with substantially all ofthe tissue lining for which necrosis is desired; heating said fluid bymeans of a heating element positioned internal to said distendablebladder; agitating said fluid by means of an agitating means positionedinternal to said distendable bladder; controlling the temperature andpressure of said fluid by control means connected to said distendablebladder; and maintaining said bladder so inflated with said fluid at atemperature for a period of time sufficient to effect cauterizationnecrosis of substantially all of the tissue lining of the body cavityfor which necrosis is desired.

The present invention also provides a method for effecting cauterizationnecrosis of a uterine endometrium or other body cavity lining comprisingthe steps of inserting a distendable bladder into the uterus, inflatingsaid distendable bladder to a predetermined pressure with a fluid sothat said distendable bladder is in contact with substantially all ofthe endometrium; heating said fluid by means of a heating elementpositioned internal to said distendable bladder; agitating said fluid bymeans of an agitating means positioned internal to said distendablebladder; regulating the temperature and pressure of said fluid bycontrol means connected to said distendable bladder; and maintainingsaid bladder so inflated with said fluid at a temperature for a periodof time sufficient to effect cauterization necrosis of substantially allof the uterine endometrium.

The present invention further provides a method for cauterizingsubstantially the entirety of the endometrium of a mammalian uterus byapplication within an inflatable bladder of a fluid at a pressure of 40to 240 mmHg and preferably about 75 mmHg, heated to a temperature of140° to 215° F. and preferably about 210° F. for a period of 4 to 12minutes, with a preference of around 6 minutes, thereby realizingsubstantial necrosis of substantially all of the uterine endometriumwithout significant damage to surrounding tissue.

The present invention also provides an apparatus for effecting necrosisof the tissue lining of a body cavity, and, in particular, substantiallythe entirety of the endometrium of a mammalian uterus comprising anapplicator which comprises a catheter for insertion into the uterus,said catheter having a proximal end and a distal end, and a distendablebladder attached to said proximal end; inflating means connected to saiddistal end for distending said distendable bladder; heating meanspositioned internal to said distendable bladder for heating saiddistendable bladder; agitating means positioned internal to saiddistendable bladder for agitating the fluid in the distendable bladder;and control means for regulating the distending and heating of saiddistendable bladder.

The present invention provides an apparatus for effecting cauterizationnecrosis of the tissue lining of a body cavity, and in particular,substantially the entirety of the endometrium of a mammalian uterinecomprising means for contacting the endometrium with an applicatorcomprising an inflatable bladder mounted on a length of rigid tubingattached to a length of flexible tubing; means for positioning thebladder in the uterus; means for distending the inflatable bladder, soas to assure substantially uniform contact with the endometrium byintroduction of a fluid under pressure into the applicator from a fluidsource positioned external to the uterus; means for heating the bladder,comprising heating the fluid by a heating element positioned internal tothe bladder; means for agitating the fluid in the bladder by anagitating means positioned internal to the bladder; control meanspositioned external to the uterus and connected to the applicator by theflexible tubing and at least one wire connected to the heating elementfor regulating the distending and heating of the bladder; and means fordisengaging the applicator from the control means so as to separate theapplicator from the control means.

The foregoing and other objects of the present invention are achieved bya method in which necrosis of the endometrium of a mammalian uterus maybe achieved by insertion of an applicator comprising rigid and flexibletubing and a readily distendable high strength bladder material into theuterus; introduction of a fluid through the tubing into the distendablebladder at a pressure of 40 to 240 mmHg and preferably about 75 mmHg,thereby inflating the bladder so that it substantially conforms to theirregularities in the shape of the endometrium; the pressure of thefluid measured and regulated by means external to the uterus; heatingthe fluid to a temperature of 140° to 215° F. and preferably about 210°F., for a period of 4 to 12 minutes, with a preference of around 6minutes, by heating means positioned within the distendable bladder andregulated by control means external to the applicator, and agitating thefluid in the bladder with an agitating means positioned internal to thebladder, thereby cauterizing substantially the entirety of the uterineendometrium.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 depicts a distendable bladder utilized in the method of thepresent invention which has been inserted into and inflated within amammalian uterus.

FIG. 2 depicts placement of the distendable bladder within a mammalianuterus;

FIG. 3 is a view of an apparatus constructed in accordance with theinvention that illustrates the applicator connections;

FIG. 4 depicts a system control unit;

FIG. 5 is a detail view of a pressure limiting and safety monitor;

FIG. 6A is the vented heating element shield utilized in the method ofthe present invention;

FIG. 6B is a cutaway view of the vented heating element shield showingthe heating element and thermocouple;

FIG. 7 depicts a means for connecting and disconnecting the applicator;

FIG. 8 is a cutaway view of an apparatus constructed in accordance withthe invention showing a shape-memory alloy agitating means;

FIG. 9 is a cutaway view of an apparatus constructed in accordance withthe invention showing a bi-metal laminate agitating means; and

FIG. 10 is a cutaway view of an apparatus constructed in accordance withthe invention showing an ultrasonic agitating means.

DESCRIPTION OF A PREFERRED EMBODIMENT

FIG. 1 shows an inflated distendable bladder 5 attached to rigid tubing3 located within a human uterus 6. Inflation of the distendable bladder5 with a fluid 25 assures uniform contact of the bladder with theendometrial tissue layer 27 of mammalian uterus 6.

The rigid tubing 3 and the attached distendable bladder 5 must besufficiently small, when the distendable bladder is deflated, so that itcan be conveniently and safely inserted into the uterus 6 through apartially dilated cervix 22. The rigid tubing with the deflated bladderis aligned with the cervical canal after the cervix is exposed with aspeculum and grasped with a tenaculum. After the distendable bladder 5has been inserted, the distendable bladder 5 should be inflated to apressure sufficient to ensure firm contact with the tissue to benecrosed, in this case the endometrial tissue layer on the interioruterine surface, but should preferably be maintained at or about 40 to240 mmHg, and preferably about 75 mmHg, to minimize risk of rupture ofthe distendable bladder 5 and possible internal injury to the patient.

Distendable bladder 5 must be capable of withstanding high temperatureswithout rupturing, and preferably have as good a heat transfercharacteristic as is obtainable in such materials to provide efficientheating action. A distendable bladder of a heat curing rubber such aslatex has been found satisfactory.

Fluid 25 preferably should be a sterile non-toxic fluid with a boilingpoint of at least 212° F. A five percent dextrose in water solution hasbeen found satisfactory.

As illustrated in FIG. 2, the uninflated distendable bladder S-attachedto rigid tubing 3 is inserted into the vagina 21, past the cervical os22, through the cervical canal 23, for placement in the uterine cavity20. Placement may be aided by virtue of scale gradations 4 located onthe rigid tubing 3 to indicate the depth of insertion of the bladder 5.Rigid tubing 3 is attached to a control unit 30 (shown in FIG. 3) viaflexible tubing 10.

FIG. 3 depicts the arrangement of control unit 30 and applicator end 1,comprising the distendable bladder 5, rigid tubing 3 and flexible tubing10, and the interconnection of those elements. A fluid system 55comprises that portion of the invention through which the fluid 25travels, including a hypodermic barrel 14 or other fluid source (notshown), flexible tubing 10, rigid tubing 3, distendable bladder 5 andcontrol unit 30. Manipulation of the hypodermic barrel 14 enables theoperator of the system to control the amount of fluid 25 in the fluidsystem 55, inflation and deflation of the distendable bladder by addingor removing fluid, respectively, and pressure of the fluid 25 in thesystem. Hypodermic barrel 14 also provides protection for the patient byallowing fast and safe reduction of excessive pressures in the systemthat might build up through some malfunction.

Manipulation of the hypodermic barrel 14 by depressing a plunger 60causes fluid 25 to be introduced through 3-way stopcock 12 into theflexible tubing 10, and to the rigid tubing 3. The fluid 25 emerges fromrigid tubing 3 and into distendable bladder 5, forcing distendablebladder 5 to expand into contact with the endometrial tissue layer 27 ofthe uterus 6. The fluid 25 is also directed along the flexible tubing tothe control unit 30 allowing measurement of the fluid pressure withinthe bladder by well known means.

Each of the parts of the fluid system 55 is in fluid communicationproviding constant fluid pressure within the entire fluid system 55 andallowing measurement of the pressure at the applicator end 1 viameasurement of pressure of the end attached to the control unit 30.

Control unit 30 is connected to applicator end 1 via plastic sheath 15which contains flexible tubing 10 and electrical sheath 16. Flexibletubing 10 is connected to a fluid joint 56 via pressure transducer 54,by well known means. Using a standard luer lock connector 19, pressuretransducer 54 and hypodermic barrel 14 are connected to flexible tubing10 via a readily available 3-way stopcock 12. 3-way stopcock 12 may beused to isolate the hypodermic barrel 14 or other fluid source from thefluid system 55 once the desired fluid pressure is reached.

FIG. 4 depicts control unit 30, consisting of fluid temperature control31, fluid pressure control 34, time control 38', agitator control 100,and a power source (not shown). The control unit 30 includes a powerswitch 42 and fuse 41. Fluid temperature is regulated by fluidtemperature control 31 and is set by temperature set/reset button 33.The temperature of fluid 25 in the distendable applicator 5 is shown attemperature display 32. The temperature of agitator means 101 and 102 isdisplayed at agitating means temperature display 104.

Fluid pressure within the fluid system 55 is regulated by means ofcontrols located on fluid pressure control panel 34. The upper limit forfluid pressure is controlled by high pressure set/reset button 35, withthe lower limit controlled by low pressure set/reset button 36. Fluidpressure in mmHg is shown by LED pressure display 37. Control unit 30also has pressure indicator display 43, which upon introduction of fluid25 into the fluid system 55 provides an easy to see visual display offluid pressure within the fluid system

Time for the procedure is shown at time display 38, which displays bothlapsed time and time remaining for the procedure. Total time for theprocedure may be easily set in minutes, seconds, and tenths of secondsusing time set buttons 39 and may be cleared or reset using timeclear/reset button 40.

A simplified means for determining whether the fluid 25 is within thepreset pressure range is depicted in FIG. s, which illustrates thepressure indicator display 43. The pressure indicator display 43 iscomprised of a low pressure indicator 51, a high pressure indicator 52and an optimum pressure indicator 53. As fluid 25 is introduced into thefluid system 55 by manipulation of hypodermic barrel 13, the pressureindicator display 43 is successively illuminated as various fluidpressures are reached. Low pressure indicator 51 is illuminated whenfluid pressure is below the preset range. High pressure indicator 52 isilluminated when fluid pressure is above the preset range. Optimumpressure indicator 53 is illuminated when fluid pressure is within thepreset range.

These indicators allow the practitioner to readily reach the presetpressure range by varying the amount of fluid in the fluid system viamanipulation of the hypodermic barrel 14. A separate heating elementindicator 55 is also provided to indicate when power is being providedto a heating element 44 located within the distendable applicator 5.

Two views of heating element 44 are shown in FIGS. 6A and 6B. FIG. 6A isan external view of heating element 44, which comprises heating elementcoil shield 45 and ventilation holes 46.

FIG. 6B is a cutaway view of heating element 44, wherein wire leads 49provide power from system control unit 30 to heating element coil 47causing heating element coil 47 to heat the fluid 25 which comes intocontact with the heating element coil 47 as the fluid 25 flows throughthe ventilation holes 46. Temperature of the fluid 25 is measured bythermocouple 48 and is displayed at temperature display 32. Heat elementcoil shield 45 prevents distendable bladder 5 from contacting theheating element coil 47.

The applicator end 1 is designed to be easy to replace as shown in FIG.7, which depicts control unit end 30' and applicator end 1 of theinvention. Control unit end 30' is composed of electrical sheath 16which is attached on one end to control unit 30 and on the other end tomale electrical connector 24, which allows transmittal of power to theheating element 44. Male electrical connector 24 is readily attached ordisattached to female electrical connector 17 on the applicator end 1.

Control unit end 30' is also comprised of components from the fluidsystem 55, including flexible tubing 10 attached to 3-way stopcock 12.3-way stopcock 12 provides control over the introduction and removal offluid 25 via hypodermic barrel 14. The applicator end 1 is easilyconnected or disconnected from the 3-way stopcock via a luer lockconnector 19 attached to pressure transducer 54.

It may be desirable in some applications to maintain the fluid 25 in thedistendable bladder 5 at a uniform temperature. In some applications,the temperature of the fluid 25 in the distendable bladder 5 may notremain uniform because the fluid 25 closest to the heating element 47may be hotter than the fluid 25 remote from the heating element 47. Theuniformity of the temperature of the fluid 25 within distendable bladder5 may be enhanced by circulating the fluid 25 within distendable bladder5.

FIGS. 8, 9, and 10 show embodiments of the invention in which theapparatus is provided with agitating means to circulate the water withinthe distendable bladder 5 so as to promote a substantially uniformtemperature of the fluid 25 within the distendable bladder 5. Theagitating means may be selected from a variety of agitating meanssuitable for this purpose which move or oscillate in response toelectrical or thermal stimulation.

FIG. 8 shows an embodiment in which the agitating means is ashape-memory alloy 101 available from the Furukawa Electric Co., Ltd.,1270 Avenue of the Americas, New York, N.Y. 10020. FIG. 9 shows anembodiment in which the agitating means is a bi-metal laminate 102. FIG.10 shows an embodiment in which the agitating means is an ultrasonicvibrator 103. The agitating means may also be a magnetostrictiveoscillator. A flexible supplementary agitating means 110 may be attachedto agitating means 101, and 102, to provide additional agitation offluid 25. The supplementary agitating means 110 is not required in theembodiment utilizing ultrasonic agitating means 103. The agitating means101, 102, and 103, may be energized via the same electrical leads 49used to energize heating means 47. The agitating means 101, 102, and103, may also be activated via a mechanical activating means such as awire or a thread controlled by the operator. In a preferred embodiment,agitating means, 101, 102, and 103 are energized via wire leads 105which energize agitating means 101, 102, and 103 independently of leads49. The temperature of agitating means 101 and 102 is measured bythermocouple 106 and is displayed at agitating means temperature display104.

In the embodiment shown in FIG. 8, the agitating means is a shape-memoryalloy 101 which forms a finger like projection projecting into agitatingchamber 107. To prepare the shape-memory alloy agitating means 101, asubstantially straight length of shape-memory alloy 101 having alongitudinal axis and a first end and a second end is clamped at thefirst end and heated to a temperature sufficient to allow the alloy tomemorize its shape. While the shape-memory alloy is at this "hot"temperature, the second end is bent in a direction away from thelongitudinal axis for a period of time sufficient for the shape-memoryalloy 101 to memorize the "hot" position shape. The shape-memory alloy101 is then allowed to cool. When the temperature of the shape-memoryalloy 101 cools below the memorized "hot" position temperature, thesecond end will return to its "cold" position along the longitudinalaxis. The shape-memory alloy agitating means 101 is then positionedwithin heating element coil shield 45. An optional supplementaryagitating means 110 may be attached to shape-memory alloy agitatingmeans 101 as shown in FIG. 9.

The shape-memory alloy agitating means 101 may be connected to wireleads 49 which can be used to energize and heat it to a temperaturesufficient for it to assume its memorized "hot" position. In a preferredembodiment, the shape-memory alloy agitating means 101 is connected towire leads 105 which energize shape-memory alloy 101 independently ofleads 49 which energize heating coil 47. In operation, agitating meanscontrol 100 is activated to provide electricity via leads 105 or 49 toshape-memory alloy agitating means 101. The shape-memory alloy agitatingmeans 101 acts as a resistor and gets hot in response to the electricalstimulation. When the temperature of the shape-memory alloy agitatingmeans 101 reaches its memorized "hot" temperature, the shape-memoryalloy agitating means 101 will move away from its "cold" position alongthe longitudinal axis to its memorized "hot" position away from thelongitudinal axis. Thermocouple 106 measures the temperature of theshape-memory alloy agitating means 101 and displays it at agitatingmeans temperature display 104. The agitating means control 100 may beadjusted so that when thermal couple 106 detects that shape-memory alloyagitating means 101 has reached its memorized "hot" temperature,agitating means control 100 will automatically interrupt the electricalsupply to shape-memory alloy agitating means 101. The fluid 25 (which isat a temperature below about 215° F.) surrounding shape-memory alloyagitating means 101 cools the shape-memory alloy agitating means 101 toa temperature below its memorized "hot" temperature and shape-memoryalloy agitating means 101 returns to its "cold" position. The agitatingmeans control 100 may be adjusted so that when thermocouple 106 detectsthat shape-memory alloy agitating means 101 has returned to atemperature below its "hot" temperature the agitating means control 100will again energize shape-memory alloy agitating means 101 for a periodof time sufficient to again heat it to its memorized "hot" temperature.By repeating the cycle of moving the shape-memory alloy agitating means101 back and forth from its "cold" and "hot" positions, the shape-memoryalloy agitating means 101 will agitate the fluid 25 within thedistendable bladder 5 causing the fluid 25 to circulate withindistendable bladder 5, through ventilation holes 46, and around heatingelement 47, thus enhancing the uniformity of the temperature of thefluid 25 within the distendable bladder 5.

In the embodiment shown in FIG. 9, the agitating means is a bi-metalagitating means 102 formed by laminating two metals 108 and 109 havingdifferent coefficients of expansion. Metals suitable for this purposeare well known to those skilled in the art and should be selected forthe temperature ranges envisioned in the applications of this invention.

Electricity is supplied to bi-metal agitating means 102 for a period oftime sufficient to heat bi-metal agitating means to a temperature higherthan the temperature of the fluid 25 within distendable bladder 5. Theelectrical stimulation causes metal 108 and metal 109 to heat and expandat different rates because of their different coefficients of thermalexpansion causing bi-metal agitating means 102 to bend in a "hot"direction. When the predetermined hot temperature has been reached, assensed by thermocouple 106, the electrical supply to bi-metal agitatingmeans 102 is automatically interrupted. The fluid 25 within thedistendable bladder 5 cools bi-metal agitating means 102 causing metal108 and metal 109 to contract at different rates because of theirdifferent coefficients of thermal expansion causing bi-metal agitatingmeans 102 to bend in a "cold" direction. As this cycle is repeated,bi-metal agitating means 102 oscillates from its "cold" to its "hot"position and agitates the fluid 25 as previously discussed.

In the embodiment shown in FIG. 9, the agitating means is an ultrasonicvibrator 103 which vibrates in response to electrical stimulation. Inthis embodiment, thermocouple 106 is not required. The ultrasonicvibrator 103 will vibrate whenever it is energized with electricity vialeads 49 or 105. The vibrations will cause the fluid 25 to circulatewithin distendable bladder 25, through ventilation holes 46, and aroundheating element 47 as previously discussed.

The invention will now be illustrated by the following example.

EXAMPLE

The cauterization procedure is preceded by screening against cancer ofthe affected region and physical condition within established norms. APAP smear and endometrial biopsy/curettage must exclude cancer orprecancerous lesions of the uterus and cervix. If a fibroid uterus ispresent, an ultrasound should exclude ovarian masses. The uterine cavitymust be 10 cm or less in length to be suitable for the small distendablebladder size.

The patient should be post menstrual or start on Danazol, or theequivalent which causes reduction in bleeding and a thin endometrium, ata rate of 800 ml daily, from the 5th day of the previous menstrualperiod until two weeks after the procedure. She will undergo theprocedure in the ambulatory surgery unit or outpatient facility whereValium and/or Demerol can be given intravenously if there is pain duringthe heating phase of the procedure.

The applicator will be inserted after a bimanual examination andspeculum of the cervix. Dilation to 6 mm. may be required which maynecessitate a local 1% lidocaine block of the cervix. Once in place theapplicator stem protrudes from the vagina and consists of an electricalconnecting plug and rigid tubing. Placement of the applicator may befacilitated by distance markings on the rigid tubing indicating depth ofinsertion.

Upon placement of the applicator it will be connected to a control unitvia attachment of the electrical connector and flexible tubing attachedto the rigid tubing to their counterparts extending from the controlunit.

Subsequent to insertion of the applicator, the control unit will bepowered on in order to allow the practitioner to set the systemconstraints. The temperature of the fluid in the bladder will be set atthe temperature control panel and can be measured via the thermocouplelocated within the bladder. Fluid pressure constraints are set at thepressure control panel, and upon inflation of the distendable bladder byintroduction of fluid to the fluid system by depressing the plunger onthe hypodermic barrel, can be easily measured by looking at the pressureindicator lights located on the control unit.

The practitioner then proceeds to inflate the distendable bladder byrotating the lever on the 3-way stopcock in order to access the fluidsource and depressing the plunger on the hypodermic barrel which mayserve as the fluid source. The practitioner injects the fluid into thefluid system until the pressure indicator lights indicate that the fluidpressure is within the pre-set constraints. At that point, thepractitioner manipulates the 3-way stopcock to close off access to thefluid system by the fluid remaining in the hypodermic barrel. Thus, thefluid is non-circulating during the heating portion of the procedure, inpart allowing more precise measurement of fluid temperature. The volumeof fluid necessary to inflate the bladder will vary from 3 to 20 ml inmost cases in order to reach the pressure wherein the bladder issubstantially in contact with all of the endometrium.

The practitioner then turns on the heating element in order to heat thefluid to a pre-set level. The heating element in the bladder isconnected via the plug to a 12 volt system which will bring the fluid inthe bladder to the level of boiling as needed for each particular local,i.e. 190 degrees fahrenheit in Mexico City, and 212 degrees fahrenheitin New York City. Once that temperature level is reached, the systemtimer is activated to time the procedure and provide automatic turn offof the heating element at the end of a pre-set period.

Upon completion of the procedure, the 3-way stopcock is againmanipulated to allow the fluid to be withdrawn from the fluid systemcausing the distendable bladder to deflate. Upon deflation of thedistendable bladder, the applicator may be safely withdrawn from thepatient. The coagulated endometrium is then removed from the endometrialcavity with a curette, leaving the underlying surface free to formadhesions with the other opposing surfaces of the endometrial cavity.

What is claimed is:
 1. An apparatus for effecting necrosis of a uterineendometrium comprising:a catheter having a proximal end and a distalend; a distendable bladder means attached to said proximal end forinsertion into and distending the uterus; inflating means connected tosaid distal end for introducing an inflation medium into said bladder;heating means for heating said inflation medium to a temperaturesufficient to effect tissue necrosis positioned internal to saidbladder; control means connected to said distal end and communicatingwith said proximal end and said heating means for regulating theinflating and heating of said bladder; agitating means for agitatingsaid inflation medium positioned internal to said bladder; and controlmeans connected to said distal end and communicating with said agitatingmeans for regulating agitation of said inflation medium.
 2. Theapparatus of claim 1, wherein said catheter is comprised of rigid tubingat the proximal end of said bladder, and flexible tubing extendingthrough said rigid tubing from said control means to said bladder. 3.The apparatus of claim 2, wherein said rigid tubing is selected from thegroup comprising polytetrafluorothylene type tubing.
 4. The apparatus ofclaim 2, wherein said flexible tubing is selected from the groupcomprising polytetrafluorothylene type tubing.
 5. The apparatus of claim2, further comprising a positioning means for positioning saiddistendable bladder in the uterus.
 6. The apparatus of claim 5, whereinsaid positioning means comprises scale gradations on the catheter forindicating depth of insertion of said distendable bladder into theuterus.
 7. The apparatus of claim 2, wherein said inflating meanscomprises a pump means connected to said flexible tubing for pumpingsaid inflation medium through said flexible tubing so as to inflate saidbladder.
 8. The apparatus of claim 7, wherein said fluid isnon-circulating.
 9. The apparatus of claim 7, wherein said pumping meanscomprises a hypodermic barrel.
 10. The apparatus of claim 9, whereinsaid hypodermic barrel is connected to said flexible tubing by a threeway valve.
 11. The apparatus of claim 1, further comprising means fordisengaging said catheter from said control means so that the applicatorand the control means may be separated.
 12. The apparatus of claim 1wherein said distendable bladder is capable of resisting an internalpressure of at least 300 mmHg without rupturing and a temperature of atleast 250° Fahrenheit without carbonizing.
 13. The apparatus of claim12, wherein said bladder is selected from the group comprising latexrubber.
 14. The apparatus of claim 1, wherein said control means forinflating and heating said bladder comprises:volume control means;temperature control means pressure control means; and time controlmeans.
 15. The apparatus of claim 14, wherein said temperature controlmeans comprises a thermocouple for measuring the temperature of saidinflation medium fixed to the proximal end of said catheter andpositioned internal to said bladder, said thermocouple connected to saidcontrol means via a second electrical lead.
 16. The apparatus of claim14, wherein said pressure control means comprises:a pressure sensorconnected to said flexible tubing; said pressure sensor connected to apressure display means for displaying and regulating the pressure ofsaid inflating means.
 17. The apparatus of claim 14, wherein said timecontrol means comprises a clock.
 18. The apparatus of claim 17, whereinsaid clock is programmable-and connected to said temperature controlmeans.
 19. The apparatus of claim 1, wherein said control means forregulating the agitation of said inflation medium comprises:temperaturecontrol means; and time control means.
 20. The apparatus of claim 19,wherein said temperature control means comprises a thermocouple formeasuring the temperature of said agitating means fixed to the proximalend of said catheter and positioned internal to said bladder, saidthermocouple connected to said control means for regulating theagitation of said inflation medium via a second electrical lead.
 21. Theapparatus of claim 19, wherein said time control means comprises aclock.
 22. The apparatus of claim 21, wherein said clock is programmableand connected to said temperature control means.
 23. An apparatus foreffecting necrosis of a tissue lining in a body cavity comprising:acatheter comprising a length of flexible tubing having a distal end anda proximal end; a bladder means for insertion into and distending thebody cavity attached to a proximal end; inflating means connected tosaid distal end for introducing an inflation medium through saidflexible tubing and into said bladder; a heating means for heating saidinflation medium to a temperature sufficient to effect tissue necrosispositioned internal to said bladder; a control means connected to saiddistal end and communicating with said proximal end and said heatingmeans for regulating inflation and heating of said bladder; andagitating means for agitating said inflation medium positioned internalto said bladder; and a control means connected to said distal end andcommunicating with said agitating means for regulating agitation of saidinflation medium.